Event driven information system

ABSTRACT

A system for tracking and monitoring at least one item in an environment includes at least one transmitter assigned a unique identification number for the item and attached to the item and at least one receiver for receiving a first data packet which includes the unique identification number from the transmitter. At least one node computer controls the receiver, receives a second data packet which includes said unique identification number and direction-of-travel code from the receiver, and determines a location of the item from the direction-of-travel code. A controller computer controls the node computer, receives the unique identification number and the location of the item from the node computer, and stores the unique identification number and the location of the item. A central computer facility coordinates the controller computer and collects and stores the unique identification number and the location of the item for exportation from the system.

[0001] This application claims priority to U.S. patent application Ser.No. 09/558,751 filed on Apr. 21, 2000.

FIELD OF THE INVENTION

[0002] The invention relates generally to an area specific event-driveninformation system and method used to monitor and track the location ofitems and relational events within a defined environment. Based on themovement and relation of the items in the environment, the inventionperforms user-specified actions to provide warnings and/or advice ofauthorized user defined proximities or to locate the items in theenvironment through the use of peripheral warning or communicationdevices.

BACKGROUND

[0003] Computer systems and technology employing electromagneticfrequencies, such as radio frequencies, to track the location of anobject in an environment are generally known in the art. Many systemstrack items through area detection tracking. Area detection trackingcommonly uses a single computer linked to radio frequency receiversplaced periodically throughout a facility. The receivers attempt tolocate tag transmitters placed on objects in the facility. The receiversemploy a single antenna with a predetermined bandwidth. The larger thebandwidth the larger the potential tracking area to be covered but alsothe greater amount of energy required to operate the system. When thetag transmitter enters the bandwidth of a receiver, the receiverreceives an identification code transmitted by the tag and relays thecode to the computer. The computer then records the location of theobject bearing the tag transmitter based on the location of the receiverin the facility that relayed the identification code.

[0004] Area detection tracking possesses many shortcomings. First, thesystems typically provide insufficient coverage to track items to anacceptable resolution. Typically, area detection systems place receiversat stations or sites where objects are expected to be, such as the nextstation in a manufacturing process. The area detection system in thosecases is merely a location verification system. The system reports thatan item has arrived at its designated station, has arrived late, or atthe incorrect station. However, the system has no ability to locate anitem in a facility that has deviated from its designed course.Additionally, location verification systems are easy to intentionallyavoid. Because receivers are only placed in particular locations withonly a predetermined transmission receiving field, a deviant individualwith knowledge of the system or receiver technology could remove itemsfrom the facility without detection.

[0005] Area detection tracking systems also do not provide anyinformation on the direction in which an item bearing a transmitter hasmoved once it leaves the area-detection field of a receiver. Thesesystems use point-to-point-tracking schemes. These schemes track thehistory of the movement of an object as it passes within the radiofrequency fields of each receiver but cannot determine the direction ofmovement of an item. In such cases, the area detection systems provideinformation on the last recorded location of an object but provide noinformation on the object's current location until the object passeswithin the radio frequency field of another receiver. In largefacilities, such as manufacturing plants, office buildings, warehousesand hospitals, many paths of movement could branch from each areadetection point making it difficult, if not impossible, to know thecurrent location of an item when the item is not within the radiofrequency area of a receiver.

[0006] In an attempt to overcome the shortcomings attributable to areadetection systems, arrays of receivers are distributed in a grid patternwith the size of an detection area determined by the predeterminedspacing of receivers based on the width of its radio frequency field. Ina grid area detection scheme, radio frequency coverage of facility isincreased closing the space between receivers thereby providingincreased data collection and higher resolution for point-to-pointtracking—the more receivers, the closer together, the greater theability to plot the movement of the object throughout the facility.

[0007] Grid area detection systems carry serious disadvantages. First,grid systems are typically only used in smaller facilities with openfloor plans such in manufacturing facilities for semiconductors,high-priced electronics or medical equipment. The grid area detectionsystems require many receivers in close proximity that make the capitaland installation of such a system cost prohibitive in large facilitiesor in facilities with many corridors, rooms, multiple floors, andnumerous points of ingress and egress. Second, grid detection systemsare expensive to operate in terms of energy costs to run the numerousreceivers. To minimize the operational costs of continuously running allreceivers and transmitters, motion detection devices and circuits areemployed in the facility to activate receivers only when objects are inmotion in close proximity. However, the addition of motion detectiontechnology to the system complicates operation of the detection effortsand adds additional installation and capital costs as well ascomplexities to the programming required to operate the system.

[0008] To overcome the disadvantages of the area detection methods, morecomplex tracking systems such as time-of-arrival and signal-strengthmethods have been developed to pinpoint and continuously track thelocation of an object within a facility. In such programs, receivers areplaced strategically throughout a facility. As an object moves through afacility, the exact location of an object is determined by atime-of-arrival determination based on the amount of time it takesmultiple receivers to receive a transmission from an item tagged with atransmitter. Based on the timing receipt of the signal from the multiplereceivers, the computer can determine the location of items bycorrelating the time differential of signal receipt as a distance of theobject from each receiver. Likewise, a signal-strength method determinesthe location of an object from the strength of its transmission receivedby multiple receivers. Here, signal-strength directly correlates withthe distance of the object from the receiver, with the transmissionsignal being stronger the closer it is to a receiver.

[0009] The time-of-arrival and signal-strength methods also havedisadvantages. Although these systems can determine the exact locationof an object, they can only do so if the transmission from an objectfalls within the radio frequency area of at least three receivers.Accordingly, many receivers must be placed throughout a facility toprovide sufficient coverage. Additionally, the tag transmitter assignedto an object often must transmit through walls, machinery and otherobstructions that may absorb the transmission from the transmitter ofthe object introducing unpredictable levels of attenuation of signalstrength or time delay in the receivers' receipt of the signal.Obstructions may also deflect or reflect the signal of the transmitterprojecting a false or ghost signal that does not correspond with thetrue location of the object. The time-of-arrival and signal-strengthmethods of tracking also involve complex transmitter and receivercircuitry and computer algorithms to determine the location of an itemfrom the signal receipt by multiple receivers adding to the cost of thesystem and operational complexities. Because of these constraints, suchsystems typically are employed in small manufacturing facilities andoffices where valuable items are often transported throughout thefacility requiring continuous and detailed information on the itemswhereabouts.

[0010] Prior art radio frequency locating systems use single-frequencytechnology in locating systems. A limited number of other radiofrequency locating systems use spread-spectrum radio communications inthe high megahertz frequency ranges. Operation in the high frequencyranges is required to provide a larger bandwidth to increase the area ofdetection and the strength of the detection field over the area. Becauseof operation at these high frequencies, Federal CommunicationsCommission licensing may be required to operate the system. Othersystems may be operated in ranges not requiring licensing but mayinterfere with other systems in the facility such as telecommunicationsystems, computers, and equipment sensitive to the radio frequencies.Additionally, other systems in the facility may also emit radiofrequencies in close proximity to the signal of the transmitterintroducing noise that will project false locations or interfere withthe calculations performed by the system to determine the location of anitem.

[0011] Some low frequency detection systems are also known in the art.In these systems, transmitters operating in low frequency rangestransmit identification information from low range transmitters toreceivers to log the location of a person or object. These systemsbecause of the inaccuracy and stability of low-frequency transmissionsrequire close proximity transmissions between the transmitter and thereceiver. This transmission range is nominally two feet or less. Suchsystems may require passing or waving the transmitter next to or nearthe receiver or even a more active component of swiping the transmitterthrough a component linked to the receiver such as magnetic card readeror a scanning device. The close proximity required to record atransmission from the identification transmitter makes such systemsunreliable to passively locate and monitor items in a facility.

[0012] Moreover, prior art radio frequency location systems are oftenineffective in tracking the location of individuals in a facility.Individuals in a facility often find the continuous tracking of theirlocation as invasive and will attempt to evade continuous monitoring oftheir location by avoiding receivers when and where possible.Intentional avoidance of receivers by individuals makes tracking theindividuals as well as other objects that they may be transportingdifficult and at times inaccurate.

[0013] Finally, prior art radio frequency location systems provide thelimited role of documenting movement of an item or verifying itslocation in a facility. In some cases, the continuous monitoring of anitem may be reviewed and evaluated to track down the last known locationof an object or to determine that an item has deviated from its expectedcourse in the facility. In such cases, reactive measures can be taken bypersonnel in the facility to either locate the object or attempt tolearn why the item deviated from its expected path. However, prior artsystems do not provide real-time responses to the movement of items in afacility to attempt to stop or curb the unauthorized movement of an itemby communicating warnings to alert the mover of the item of theunauthorized activity, alerting security, and enabling users of thesystem to proactively locate an item in the facility. Prior art systemsdo not provide immediate response and action to the unauthorizedmovement or activity associated with an item. In the same course, knownarea detection systems are not coupled with third party communicationand response devices in a facility to permit the system to utilizesystems already present in the facility to aid in the location of anitem or to immediately respond to unauthorized activities.

SUMMARY OF THE INVENTION

[0014] Large facilities, like hospitals, manufacturing plants,engineering facilities and the like cover large areas over multiplefloors. Each of these facilities have items (inanimate objects as wellas people) that need to be tracked. Items such as files, tools, andequipment are often missing, misplaced or even stolen. Items such aspersonnel, workers, patients and visitors become lost, wander into anunauthorized area, or leave a facility without others knowledge of theseevents. Much too often people commit unauthorized acts moving andmisplacing equipment or removing an item from an environment altogetherfor their own personal gain or use. The cost associated with replacingstock or missing equipment and the time lost searching for misplaceditems in a large facility can be enormous.

[0015] The instant invention is directed to an area-specific trackingand event-driven response system for tracking and monitoring items in afacility environment and providing actions in the environment inresponse to the current location or movement of an item. The systemoperates by assigning a configurable identification device, such as abadge or tag, embodied with a transmitter designed to emit a uniqueidentification number assigned to each item. The identification deviceattaches to or is worn by each item to be tracked in the environment.The transmitter in each identification device operates through the useof near field radio frequencies that accurately sends the transmitteddata through a transmission range of up to two meters from thetransmitter without interfering with the operation of other electronicequipment in the environment or degrading the transmission because ofthe presence of other electronic equipment emitting similar radiofrequencies.

[0016] The environment in which the system operates is divided intodomains that correspond to discrete and sectional areas of the facilitysuch as separate floors or departments. All items in a domain aretracked by a controller computer that manages the system functionalitiesin the domain. Each domain is further subdivided into zones. Zonestypically encompass individual rooms, halls, closets, and other areas ina domain defined by a portal, a point of ingress or egress such as adoorway, elevator, escalator, or stairs, between zones in the domain orbetween domains themselves. A node computer assigned to track items in azone connects to the controller computer for the domain that containsthe zone.

[0017] A node computer connects to a receiver supported by a first andsecond antennas configuration generating adjacent and overlapping firstand second receiving regions for receiving signals emitted from nearfield inductive or low frequency electromagnetic fields generated by thetransmitter assigned to each item. These low frequency electromagneticfields are generated in a pattern whereby an item passing through aportal must consecutively pass through the first and second receivingregions in a specific order. The order by which an item bearing anidentification device passes through the first and second receivingregions at the portal determines the direction-of-travel of the iteminto or out of a zone. When a item passes through a receiving region,its identification device emits a signal of a first data packet whichincludes the unique identification number that is received through thefirst and/or second antenna corresponding to the receiving regionthrough which the item has passed. The receiver sends to the nodecomputer a second data packet which includes the unique identificationnumber of the item and a direction-of-travel signal that corresponds tothe antenna that received the transmission. The node computer verifiesthese signals.

[0018] The node computer operates software provided with the zonelocation of the node computers and receivers in the domain, the portalthat separate zones and the receiver and node computer assigned tomonitor each portal. From the repeated direction-of-travel informationreceived by a node computer, the node computer determines the zone inwhich an item is located and the direction from which it entered thezone. The method of placing receivers at portals--physically constrainedpoints in a facility--requires less receivers to determine the locationof an item and removes the possibility that an item could evade thereceivers thus providing a high tracking rate for the movement of anitem. Additionally, the use of the dual adjacent receiving regions in aportal permits the transmitters to generate an electromagnetic fieldthat must cover an area only as large as the portal permitting the useof less powerful transmitters and receiver configurations, andcorrespondingly lower energy and operational costs for the system. Thedual adjacent low receiving regions also enable a determination of thedirection-of-travel of an item as it moves through an environmentenabling proactive responsive actions to be taken in response to or inanticipation to the movement of an item.

[0019] The node computer links with a controller computer sendinginformation received from the transmitter such as the item'sidentification number and other internally developed information likethe direction of travel information and the time associated with thereceipt of the transmitted information. In conjunction with the nodecomputer, the controller computer determines and records the location ofan item and the time the item entered that location in the environment.This process repeats each time an item bearing an identification deviceenters the receiving regions stationed about each portal. Controllercomputers maintain a record for each item that includes the location ofthe item as well as constraints to movement placed on an item, andactions to take in response to violations to the constraints to movementor violations in movement. Periodically, or upon the movement of an itemthrough a portal, the controller computer compares the location of theitem against the constraints to movement for that item. If a constraintis violated, the controller computer reviews the predefined actions tobe taken if a violation in movement occurs. Such responses involveactivating warning devices such as a user terminal or work station,electronic sign, a voice synthesizer, a monitor, or video camera toprovide warning or alarms directed to the specific unauthorized movementof the item. Additionally, the controller computers continue to trackthe unauthorized movement of in item throughout the environment andprovide the capability to activate warning devices based on theanticipated movement of the item through an environment based ondirection-of-travel of an item through portals. The response and warningcapabilities of the present invention provide more than mere informationon the location of an item but also take user programmable active stepsthroughout the environment to warn of the unauthorized movement of anitem and take anticipatory or reactive actions to attempt to curb theunauthorized movement of an item. The system also provides for thetracking of a person moving an item and responding to violation inmovement of either the person or the item by providing warnings to thatperson directly to stop an unauthorized movement through warning devicesand alarms available to the system and controlled by either the nodecomputer or controller computer.

[0020] A central server coordinates controller computers in theenvironment. The central server maintains a database of records for allitems not currently present in the environment or items in transitbetween domains. As an item moves from one domain to another, thecontroller computer monitoring the departing domain passes the record ofthe item to the central server when the item passes through a portalthat marks an exit from the domain. The central server maintains therecord for the item until the item passes through another portalpermitting the item to enter a new domain, at which time the centralserver passes the record for the item to the controller computermonitoring the new domain.

[0021] The central server is also designed to connect to third computersystems through a system interface. The central server generates reportson the status and history of locations for each item and passes thereports through an interface to a computer network and databasesmaintained in the environment independently from the system. The centralserver also possesses the ability to interface with other third partycommunication systems existing independently in the environment such ascomputer networks, telecommunication networks, and pager systems.Through the third party communication systems, the central server mayprovide information to these systems or control these systems to provideadditional alarms or warning regarding an unauthorized movement of anitem. With this adaptation, the system is capable for utilizingcommunication systems already in place in an environment therebyalleviating the cost associated with providing new, duplicative systemsor implementing new communications systems in the environment whichpeople are unfamiliar with or not trained to use.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] These and other aspects and advantages of the present inventionwill become apparent upon reading the following detailed description andupon reference to the drawings, in which:

[0023]FIG. 1 is a block diagram illustrating an example of theconfiguration of the area-directional tracking and event-driveninformation system, according to the present invention.

[0024]FIG. 2 is a block diagram illustrating the configuration of areceiver according to the present invention.

[0025]FIG. 3 is a block diagram illustrating the configuration of atransmitter according to the present invention.

[0026]FIG. 4 is a logical diagram illustrating the concept of a portaland paired antennas as a logical construct.

[0027]FIG. 5 is a facility layout diagram for an environment employingthe present invention.

[0028]FIG. 6 is a facility layout diagram for an environment employingthe present invention.

[0029]FIG. 7 is a diagrammatic illustration of a vehicle and trailerwith a container.

[0030]FIG. 8 is a block diagram of an example of an area-directionaltracking and event-driven information system applied to a transportationor shipping environment, such as an airport, according to an embodimentof the present invention.

[0031]FIG. 9 is a diagrammatic illustration of the system of FIG. 8.

[0032] The invention is amenable to various modifications andalternative forms. Specifics thereof have been shown by way of exampleillustrated in the drawings and will be described in detail. It shouldbe understood, however, that the intention is not to limit the inventionto the particular embodiments described. On the contrary, the intentionis to cover all modifications, equivalents, and alternatives fallingwithin the spirit and scope of the invention, which is defined by theappended claims.

DETAILED DESCRIPTION

[0033] The present invention is applicable to a variety of area-specifictracking and event-driven information methods and arrangements for usein a system to effect monitoring, tracking, locating, and identifying ofitems and responding to events based on time and the location of an itemin a commercial environment. The invention has been found to beparticularly advantageous for use in systems for facilitating themonitoring of items in a health care, manufacturing, and business officeenvironment where items move throughout the facility. The invention hasalso been found to be particularly advantageous to identify movements ofitems unauthorized by management of the facility and alerting managementof the unauthorized movement of the item. An appreciation of variousaspects of the invention can be gained through a discussion of variousapplication examples herein.

[0034] The present invention includes a system 20 comprised of acomputer network and deployment of multiple nodes that connect tosensors that track items in an environment 22 assigned to system 20 formonitoring. Environment 22 represents the physical area in which system20 operates and includes all items that reside or work withinenvironment 22. In actual application, environment 22 is any physicalspace including a multiple floor hospital ward, a manufacturing plant,an office building or the like.

[0035] In environment 22, system 20 tracks and monitors items. Itemsinclude any non-fixture tangible items that can be readily transportedor moved including tools, equipment, furniture, files, books, or carts,but can also include an object regardless of the mobility or immobilityof the object. Items also include subjects such as persons andpotentially other biological creatures that enter and leave environment22. Within environment 22, each item can be assigned to a particularclass and category predetermined by administrators or management ofenvironment 22 to group and identify items. The class and categorylistings are arbitrary designations provided for the user to aid in theclassification of items.

[0036] For example, eight major categories exist in system 20 includingcategories dedicated to system 20 as a whole, unique identificationnumbers, equipment, people, locations, time, vendors, and history. Bothclasses and categories can be divided into sub-classes and categories.Each class and category combination is assigned pre-determinedconstraints to movement in environment 22. A set of instructionsaccompanies each class and category combination designating action to betaken by system 20 should an item violate its constraints to movement ormove without proper authorization.

[0037] Overall, classes and categories for items can be adapted insystem 20 to conform with classifications already in use byadministrators of the finance department of a facility to conform theclasses and categories to class distinctions used to group persons basedon pay level or job responsibilities or to group assets based onpurchasing or amortization requirements.

[0038] For example, a particular class and category includes allmaintenance workers in environment 22. The maintenance workers would beassigned to the same class but to different categories. Maintenancesupervisors would be placed in a class providing a range of movementthroughout environment 22 and authorization to move all items. Incontrast, an electrician would be assigned to a different category inthe same class limiting this worker to a specific work area inenvironment 22 and authorization only to move other specific itemsnecessary to perform his job responsibilities. Likewise, inanimate itemsare also assigned to different categories and classes. Maintenanceequipment such as ladders and tools could be in a separate class fromcomputers. Each class is subdivided into categories that define therange of movement for items in the category and the personnel authorizedto move these items. For example, a ladder would be assigned to aspecific category that corresponds to constraints of movement such aslimiting use of the item to particular floor in environment 22 and to bemoved by any maintenance worker. On the other hand, a drill assigned toanother category would be assigned different constraints to movementsuch as permitting its movement throughout environment 22 but only bymaintenance workers qualified to operate that equipment. Assigned toeach class and category is a set of default instructions to be taken bysystem 20 if an item violates its constraints to movement establishedfor the class and categories. Such instructions involve actions such asactivating a warning alarm, placing a warning message on an electronicsign and/or contacting security through a user terminal.

[0039] Domains 23 subdivide environment 22 into smaller physical areas.A domain contains all identified items that exist, ingress into, andegress from the domain. Environment 22 has at least one domain, althoughpractical application of system 20 would typically require multipledomains, with each domain representing a distinct physical area inenvironment 22. Domains represent physical constraints that arestructure-specific within environment 22. For example, domains couldrepresent individual floors of a hospital ward or office building andthe various sections of a manufacturing plant such as the warehouse, theassembly floor, offices, and the maintenance shop. FIG. 1 shows domains23 labeled as D1-Dn, where “n” is determined from the layout and designconfiguration of environment 22.

[0040] Domains 23 are divided into smaller physical regions or zones.Zones 25 are typically physical rooms, corridors, and stairwells withinenvironment 22 typically defined by established barriers such as walls,floors, ceilings, bars, windows, fixed equipment and by othersubdivisions that would confine movement of items. A zone comprises atleast one portal, a point of ingress to and egress from the zone.Typically, a portal includes doorways, stairs, escalators, elevators, orother points, where items move between zones 25 within a domain orbetween domains 23 in environment 22. FIG. 1 shows domains 25 labeled asZ1-Zn, where “n” is determined from the layout and design configurationof environment 22.

[0041] A unique identification number identifies each item within system20. An identification device carries the identification number andattaches to or is carried by each item. In system 20, the identificationnumber can be any integer number, although identification numbersranging from 0 to 1,048,576 is sufficient to uniquely identify all itemsin environment 22.

[0042] Accompanying each unique identification number, at least onerecord is created such as a history file initialized for each itemintroduced into environment 22 to be monitored by system 20. A recordcomprises numerous data fields that include information about the itemand could include its class and category, a description including theactual name of the item and/or its physical identification number suchas an equipment serial number, if an object, or social security number,if a person, home location of the item, constraints to movement of theitem, actions to be taken upon violation of constraints to movement ofthe item (a violation in movement), current location of the item, andthe last time the location of the item was identified by system 20.Records may provide event and history logs or parameters defined by auser to react to the movement of an item. Data in each record field iscoded and stored in numerical, logical and character strings to beinterpretable by software that operates a central server 24, controllercomputers 26 and node computers 28. Some data fields, such as theconstraints to movement, are variable, dependent on domain where theitem is currently located. For example, an item may possess noconstraints of movement throughout an entire domain while it remains inthat domain, but could receive an entirely new set of constraints tomovement if the item is moved to another domain. Overall, constraintsare site wide, modified by location, time and association.

[0043] Central server 24 maintains the record of an item when the itemis outside of environment 22. For example, a record of an employee wouldbe maintained by central server 24 when the employee exits theenvironment 22 to leave work for the day. When the employee returns toenvironment 22 the next day, the employee passes through a portal into adomain 23. The controller computer 26 detecting the arrival of theemployee into the domain but finding that it has no record for the item,contacts central server 24 requesting the record. Central server 24checks its database for the record for the item, locates it and passesthe record through communication link 30, an Ethernet network or otherdata transfer network, to the appropriate controller computer 26 forthat domain. Upon receipt of the record, controller computer 26 updatesthe record and history file to reflect the current location of the itemin domain 23 and update the constraints to movements and violations inmovement maintained in the record, if necessary, to reflect the newlocation or time associated with the item or changed constraints enteredinto system 20 for the item. Controller computer 26 will maintain andcontinuously update the record while the item remains in the same domain23.

[0044] System 20 monitors and tracks items in environment 22 through theuse of a network of computers which could include controller computers26 and node computers 28. For example, node computers 28 identify thelocation of each item assigned to a specific domain. Node computers 28receive information based on the identification and direction-of-travelof each item through a portal and determines the location of the item inenvironment 22. Node computers 28 pass the location of the item to acontroller computer 26 which maintains the record and history file oneach item. FIG. 1 shows controller computers 26 labeled as C1-Cn andnode computers 28 labeled as N1-Nn, where “n” is determined from thelayout and design configuration of environment 22. Controller computer26 may also receive from node computer 28 the identification number ofthe item, the time of movement of the item, direction of travelinformation and other status data and perform the logical correlation oflinking the identification number of the item to location of the nodecomputer 28, and as such the location of the item in the domain. Thedetermination of the location of an item by node computer 28 orcontroller computer 26 is completed by software designed to manipulatedata programmed to correlate the physical location of the node computer28 in environment 20 in relationship to the zone 25 and domain 23designated in the environment and the direction of travel information ofthe item collected by node computer 28.

[0045] All controller computers 26 connect to a central server 24 thatcollects all records for items in domains 23, prepares the informationfor export outside the system 20 to external systems 34, throughinterface 32 which is a commercially available administrative computeror server.

[0046] A communication link 30 interconnects central server 24 tocontroller computers 26 and node computers 28. Central server 24 managesthe operation of system 20 in environment 22 by coordinating controllercomputers 26. Central server 24 comprises a central processing unit,electromagnetic storage media, memory, a network connection and externalports. Central server 24 supports the typical configuration of apersonal computer or workstation commonly known in the art withsufficient computing power, memory, storage and speed to control theoperation of the system 20 and manage the manipulation of data collectedfrom environment 22. An uninterruptible power supply connects to centralserver 24 to provide temporary back-up energy to maintain allfunctionalities of central server 24 in the event of a power loss inenvironment 22. Each controller computer 26 also provides anuninterruptible power supply, which supplies power to all of the nodecomputers 28 connected to the controller computer 26.

[0047] Central server 24 operates through a commercially availableoperating system. Central server 24 runs software that stores allsystem-wide information such as the class and categories for all items,routing all operational instructions, collecting data and records onitems stored by controller computers 26 to supply information on thelocation of items for exportation to external systems 34 in environment22 that are not controlled or managed by system 20. Additionally,central server 24 maintains a transitional database that temporarilystores records from controller computer 26 on each item in transitbetween domains and items that have left environment 22 altogether. Thesoftware operated by central server 24 uses programming techniquescommonly employed in the art to accomplish the desired functionalitiesand provide a user of system 20 an easy to use, single point to programand configure system 20 and collect data therefrom.

[0048] A programmatic link 31 connects central server 24 to interface 32to permit the programming of central server 24, controller computers 26,and node computers 28 and the exportation of data collected from system20 to external systems 34. Link 31 provides a firewall that protects theinternal functioning of system 20 from inadvertent or erroneousprogramming that could otherwise be introduced at interface 32.Generally, interface 32 is a personal computer with a standardconfiguration readily known in the art. Programmatic link 31 prohibitsthe transfer of unauthorized data or uploading of foreign software tocentral server 24, thereby providing a firewall against corrupt data andviruses that may otherwise impede operation of system 20 or damage thehardware and software components of system 20. Programmatic link 31comprises a data cable through which data may be transferred fromcentral server 24 in interface 32, however, it is appreciated that anynetwork technology such as fiber optics, radio, optic transmissions,infra-red or others known in the art, could be employed.

[0049] Interface 32 is designed to manage all tasks associated withinterfacing and coordinating system 20 to environment 22. Real-timeevent processing internal to the system 20 is manipulated via tokenizedrecords, multi-dimensional array pointers, that increases processingspeed. Through interface 32, user and system functions governing system20 are programmed and designed aiding real-time event processing forsystem 20. Interface 32 may also coordinate the transfer of records andhistory files between controller computers 26 when an item moves betweendomains 23.

[0050] Software programmed through means commonly known in the artoperates in interface 32 and manages the information to be passed toexternal systems 34 for further recordation and processing. Interface 32connects system 20 to external systems 34 to provide informationcollected by system 20 on a historical and record-keeping basis.Interface 32 provides data files in ASCII format or other formatcompatible for exportation and interpretation by databases 35, labeledas DB1-DBn, in FIG. 1, where “n” is determined by the facilityencompassing environment 22. Databases 35 maintain records on financialinformation, inventory, equipment use, depreciation of equipment,quality control statistics, payroll, and other data managed by thefacility. Through interface 32, a user requests central server 24 togenerate reports on the status and history of items in environment 22.Central server 24 contacts controller computer 26 to obtain records andhistory files on each item and generate reports from that data.

[0051] Interface 32 receives reports through programmatic link 31 andmakes the reports available via a terminal associated with interface 32or directs the reports to databases 35 for storage, manipulation, orevaluation independent of system 20. Reports requested through interface32 can be for a single item, all items, or any grouping therebetween.Interface 32 also automatically accesses reports generated by centralserver 24 periodically on a delay basis to back-up system 20 andmaintain a record of use of each item for historical reference aftersystem 20 purges the history files maintained for each item to freememory and storage space within system 20.

[0052] Interface 32 also sends information to workstations 37 positionedthroughout environment 20 to provide real-time information on the statusof particular items or to provide warning messages relating tounauthorized movement of an item. In FIG. 1, workstations 37 are labeledas W1 to Wn, where “n” is determined from the layout and designconfiguration of environment 22. Workstations 37 are commerciallyavailable personal computers operating under commercially availableoperating system and running a system interfacing software linkingworkstations 37 to interface 32 through communications links 39. Thesystem interfacing software provides a window projected on the desktopsof workstations 37 for displaying the real time information or warningmessage received from central server 24 through interface 32.Workstations 37 can be placed throughout environment 20 at locationswhere real-time information on the status of an item is necessary suchas at a security office or administration office. Additionally, system20 can provide real-time information on items to workstations (notshown) located outside of environment 22 through communications links 33which accesses or controls third party communication system 80 such astelephone or data lines, if monitoring of items within environment 22has been out-sourced such as to a third-party security company.

[0053] Workstations 37 also perform the role of assigning items tosystem 20. Through the system software, an authorized user of system 20may add, edit, or delete a record for an item in environment 20. Throughthe software window, the user may input the information assigned to therecord of each item. Such information includes its unique identificationnumber used by the system, the name of the item (persons name, equipmentdescription), identification number (employee's ID number, patientnumber, equipment identification number), the home or base location forthe item in environment 22, constraints to movement, and actions inresponse to unauthorized movements. Additionally, the items may beassigned to a class and category through workstation 37 therebyautomatically assigning default values for a variety of information inthe record for the item including the home location, constraints tomovement, and responses to restrictions to constraints to movements.

[0054] To provide easy input, modification, and interpretation ofrecords, especially the constraints to movements and responsive actions,the system software operating on workstations 37 permits an authorizeduser to enter information in a sentence and phrase form that creates arelationship command. The relationship command uses a list of predefinedphrases that identify actions, classes, and categories. These phrasesare available in the system software on workstation 37 in a menu drivenformat with the actual commands provided for use in the system variabledepending on environment 22 and constraints imposed by administrators ofenvironment 22.

[0055] Once a record is created for an item, the unique identificationnumber assigned to the record corresponds with the identification numberassigned to an identification device to be affixed to an item. Thelocation of the item is inputted into system 20 and the record for theitem by passing the identification device under a receiver 48 inenvironment 20, which in turn transmits the unique identification numberto a node computer 28 which determines the location of the item and inturn passes the location information relating to the uniqueidentification number to a controller computer 26 responsible formaintaining all records for items in the domain.

[0056] Overall, relationship commands are groups of phrases dedicated toidentifying the class, category and unique identification for each item.The software permits multiple sentences to comprise a relationshipcommand to be applied to a particular item or as a default for an entireclass or category of items. Phrases in the relationship command definethe events that trigger the start of constraints of movement and thetime and locations associated with such constraints. For example, arelationship command regarding an Item X, a pump, could be createdthrough the system software as follows: “Starting now, equipmentclassified Medical in category Pumps and named Item X must not be out ofArea Y for longer than a period of n years, n months, n days, n hoursand n seconds, or a terminal alert with audible alarm will be sent touser terminal Z saying ‘Medical equipment of category Pump named Item Xhas exceeded its allotted time out of Area Y.”’ This same relationshipcommand broken down into user-selected phrases (phrases in “( )”)provided in menus by the system software: “(Starting now,) equipmentclassified (Medical) in category (Pumps) and named [Item X] (must not)(be out of) (Area) [Y] (for longer than) (a period of) [n] (years,) [n](months,) [n] (days,) [n] (hours) and [n] (seconds,) (or) (a terminalalert) (with audible alarm) (will be sent to) (user terminal) [Z] saying(‘Medical equipment of category [Pump] named [Item X] has exceeded itsallotted time out of Area [Y].’)” Phrases in □ correspondingly apply toan item's specific information or constraints. Additionally, defaultrelationship commands that apply to all items in a category can becreated through using the name of the category instead of the name of anitem when creating the relationship command. The relationship command isparsed by system 20 with the information from the relationship commandbroken down and stored in various fields of the record for the item foreasy interpretation and evaluation of the record by system 20 by methodscommonly-employed in the art. In all cases, the actual relationshipcommands entered by the authorized user through workstation 37 arestored by system 20 and displayed for each item when modifications tothe relationship command is necessary.

[0057] Central server 24 connects through communications links 30 toeach controller computer 26. Controller computers 26 also connectdirectly to each other through communications links 30. Generally,controller computers 26 interact through the coordination of centralserver 24 transferring records on items moving through domains monitoredby different controller computers 26. Communication links 30 employcommercially available network structure and conductivity protocolscommonly known in the art such as Ethernet, however it is appreciatedthat other network technology now known or to be developed that permitsthe transfer of data could alternatively be employed.

[0058] Controller computers 26 comprise a commercially available centralprocessing unit, electromagnetic storage media, memory, databoard, and anetwork card. Each controller computer 26 is also connected to anindependent uninterruptible power supply to provide temporary back-upenergy to maintain all functionalities of controller computers 26 andnode computers 28 in the event of a power loss in environment 22.Controller computer 26 also includes at least one node computerinterface enabling a connection of controller computer 26 to at leastone node computer 28 via a communication link 38. In one embodiment,communication link 38 is a multi-drop network permitting the transfer ofdata and power between controller computer 26 and node computer 28,however, communication link 38 may provide connectivity and conductivitybetween controller computer 26 and node computer 28 through a variety oftechnology known or to be developed in the art. In application, eachcontroller computer 26 can connect to a maximum of 64 independent nodecomputers 28, although it is appreciated that advancement in technologyor reconfiguration of controller computer 26 by one of ordinary skill inthe art could permit connection of each controller computer 26 to agreater number of node computers 28.

[0059] Controller computers 26 also connect to and interface with thirdparty communication systems 80 that operate within environment 22. Thirdparty systems 80 include pager system 82, a telephone/cell phone system84, or email system 86. Dependent on the action of an item, controllercomputers 26 access the third party system to provide a warning or senda communication to an item requesting that specified action be taken.For example, if an emergency occurs requiring the immediate attention ofperson X in environment 22, a user of system 20 may access user terminal56 to request that a page be placed through pager system 82 or a call beplaced directly to the cell phone of person X via telephone system 84located in environment 22.

[0060] Each controller computer 26 connects to at least one nodecomputer 28 specifically designed to collect data on the location andmovement of items. Node computer 28 is a commercially available,low-power embedded controller comprising a central processing unit andmemory. Node computer 28 is assigned to particular domain 23 andcommunicates with the controller computer 26 that controls that domainthrough a network interface connected to a multi-drop network 38 thatalso supplies power from controller computer 26. At least one serialport and at least one parallel port extend from node computer 28permitting the node computer 28 to operate receivers 48 (T1, T2, . . .Tn) for monitoring and tracking items and communicating with a varietyof peripheral devices 50 for alerting or warning users of system 20 asto the status, location, and violations of constraints of movement of anitem. In one embodiment, each node computer is equipped with 4 serialports and a single parallel port. Through serial ports, node computer 40collects information on the location and direction-of-travel on itemsfrom receivers 48 or transmits data to provide a user-defined responseto the movement of an item through peripheral devices 50.

[0061] The processing unit of node computer 28 comprises a two boardset. A first board supports the four serial ports and two parallelports. A second board provides power supply and interfacing functions. Afirst serial port is used for the interface to network node computer 28to controller computer 26. Remaining serial ports associated with nodecomputer 28 pass through protection circuitry then to the three externalports to connect to related equipment such as a receiver 48. A firstparallel port is used to read an identification number assigned to eachnode computer 28. The identification number distinguishes each nodecomputer 28 from other node computers 28 networked to the samecontroller computer 26. A second parallel port is split to comprise atwo bits per external port permitting node computer 28 to identify thetype of device connected to it, such as a receiver 48. Power is alsopassed through these external ports of node computer 28 to powerconnected devices like receivers 48.

[0062] Receivers 48 are configured to receive electromagnetic signalsfrom near field inductive, low frequency proximity transmitters,although receivers 48 could also receive signals from other transmittingdevices operating through radio frequency, magnetic. infrared, oroptical transmissions.

[0063] In one embodiment, the receivers 48 operate at low frequencieswhich will not interfere with other equipment in environment 22. In oneembodiment, the receivers 48 operate at a frequency of 125 kHz or less.However, it should be noted that the frequency at which the receivers 48operate will be dependent upon the equipment in the environment 22, andthus, the present invention is not limited to any specific frequencyrange. Most equipment sensitive to radio waves is sheltered from belowfrequencies of 125 kHz thereby permitting the operation of receivers 48in environment 22 without interfering with other equipment. Anyfrequency avoiding interference with surrounding equipment inenvironment 22 could be employed. At least one receiver 48 is placed ineach zone 25 about the portal into and out of the zone. Additionally, atleast one receiver is placed at each portal separating domains 23, zones25, and all portals permitting ingress and egress from environment 22.

[0064] In another embodiment, the receivers 48 use ultra wide bandtechnology and are further adapted to determine a distance between thereceiver 48 and a transmitter 90. The system may also be adapted totrack and store location information (two dimensionally orthree-dimensionally) based on signals received from the receivers 48.

[0065]FIG. 2 illustrates the configuration of the receivers 48 of thepresent invention. Receivers 48 include a first external antenna 61 andsecond external antenna 62 that receive a first data packet emitted fromtransmitters associated with identification device 60. Antennas comeinto programmable gain amplifiers 63, with gain controlled bymicrocontroller 64. The amplified signal passes through filters 65.Filters 65 and amplifiers 63 provide impedance matching and 10 dB ofon-frequency gain resulting in a narrow bandwidth. In the presentinvention, filters 65 are active, six pole Bessel filters although it isunderstood that other filters of varying configurations and operatingparameters commonly employed in the art could be employed. Antennas61-62 are active, modified loop antennas. The loop dimensions are2″×24″, with an open-air coil of 30 mH. The combination of the activeantennas 61-62 and filters 65 result in a very narrow bandwidth bandpassresponse. At 32 KHz and 66 KHz, attenuation is −68 dB, assuming acenter-frequency 46.607 KHz reference of 0 dB.

[0066] The outputs of filters 65 are read by an integrated 10 bit analogto digital converter 66 designed to convert the analog signal receivedto a digital data packet for subsequent normalization and dataextraction. Data is processed in real time upon identification of asignature START data associated with the data packet received fromidentification device 60. Once the first data packet is received, thepacket is buffered in RAM associated with converter 66. Enough RAM isprovided for eight data packets to be recorded. Time required for asingle packet to be transmitted is 33.3 mS, although it is known in theart that various data transfer schemes and protocols could be employedthat could enhance the data transfer rate thereby reducing the transmittime. At the end of the acquisition phase, the first data packet isprocessed via a three-pass normalization and data extraction algorithmprogrammable by one of ordinary skill in the art. This processing isdone in the background, while data acquisition continues in theforeground. Gain control is managed by the foreground processing routineto prevent filter saturation. A semaphore flags any changes to the gaincontrol register for subsequent handling by the data recordingsubroutine in the event a data packet is currently being recorded.Background processing time is significantly less than packettransmission time, so it is expected that in use only two buffers willbe in use (one containing the completely received data packet, onebuffering the in-process packet). An antenna channel identifier isappended to the 4 byte binary second data packet. Overall, receiver 48receives and decodes the packet, performs error checking if necessary,converts the first data packet to a second data packet which encompassesa three byte binary string which includes a direction-of-travel codeassociated with a prefix byte corresponding to antennas 61-62 thatreceived the first data packet from the transmitter. The second datapacket is then transmitted to node computer 28 through a universalasynchronous receiver transmitter (UART) 67 which links to acommunication link 68 such as serially via the RS-232 port. However, itcan be appreciated that the UART 67 and communication link 68 can beemployed through any variety of devices and the processing andconfiguration of data used by receiver 48 could be arranged throughvarious means and protocols commonly known in the art.

[0067] Microprocessor 64 driving the receipt of the first data packetand conversion to the second data packet is an Atmel AT family embeddedRISC microcontroller running at 6 MHz, although it is known that variousother commercially available microcontrollers could be employedoperating at the same or other speeds. An internal counter/timer circuitgenerates a clock, which triggers converters 66 and generates theinterrupt for the real-time clock. Power for the receiver is provided bya node computer 28 with power for the active antennas 61-62 passingthrough receiver 48 from node computer 28. Peripheral devices 50 includea video monitor 52, visual messaging device 54, a user terminal 56, avoice output module 58, a video or cctv camera 59 as well as otherdevices known to or to be developed in the art to outputting warningmessages, alarms, or signals. Peripheral devices 50 provide directwarnings or alarms in response to violations in constraints to movementsto warn an item of an authorized movement directly or alert a personwith responsibility over an item of the violation of the constraint ormovement so that responsive action can be immediately taken. In oneembodiment, node computer 28 is equipped with four serial ports, threeports assigned to receivers 48 and one to other peripheral devices 50,although one of ordinary skill could appreciate that additional serialports could be added to node computer 28. Software accompanying nodecomputer 28 provides the functionality to operate the alarm and warningdevices enabling node computer 28 the ability to communicate withperipheral devices 50 connected to node computer 28.

[0068] Each node computer 28 operates non-volatile core software throughits controller. The software is developed through commonly knowncomputer programming language and operates in a 16-bit environment. Thesoftware controls communication between node computer 28 and controllercomputer 26 via communication link 38, pulsing and reading time-criticaltransmissions from receivers 48, and passing data to peripherals devices50 to activate the capabilities of these devices.

[0069] Configurable identification devices 60, such as badges or tagslabel items assigned to be tracked and monitored by system 20.Identification devices 60 comprise a transmitter 90 operated by anindependent power source, like a battery, and programmed with anidentification number. A casing encloses transmitter 90 and its powersource. In one embodiment, identification devices 60 possess the lengthand width of a standard credit card. An identification device 60 affixesto an item through the use of an adhesive or other form of adherencesuch as velcro®, a button, magnet or strap. Items such as people wearidentification devices 60 as a name or identification tag or as part ofan identification band worn on a wrist. Transmitter 90 of eachidentification device 60 rapidly emits a periodic low frequency, nearfield, omni-directional electromagnetic transmission field through whicha signal encoded with first data packet is encoded. The transmissionfield generated by identification devices 60 is shaped like twotruncated cones, with their apex at the transmitter coil. The fieldprovides a transmission range extending up to six feet or two metersfrom transmitter 90, although it is appreciated that the field diametermay vary depending on the needs of system 20. The transmission range oftransmitter 90 permits accurate identification of data from transmitter90 by receiver 48 from a range sufficient to cover the typicalcross-sectional dimensions of portals such as doorways, stairwells, andhallways. The transmission range promotes the passive benefits of system20 by permitting the continuous identification of items in environment22 as the items generally move about or are moved about environment 22without requiring the items to move in a predetermined path or withactive additional movements to pass identification device 60 by receiver48 in close proximity, such as in close proximity systems that requirescanning or near-distance proximity of two feet or less between thetransmitter and receiver to effect transfer of data.

[0070]FIG. 3 illustrates the internal structure of transmitter 90.Transmitter 90 is controlled by microcontroller 91 that receivesinformation inputs from clock 92, non-volatile ID EEPROM(electrically-erasable programmable read-only memory) 93 and statusinputs 94 to emit a signal at a carrier frequency of 47.607 KHz, with a600 Hz AM modulation scheme, although any frequency below 125 KHz couldbe utilized that matches the frequency of receivers 48, enablingreceivers 48 to pick-up the signal of identification device 60 when thefield generated by the transmitter passes within the receiving range. Acarrier frequency emitted from transmitter 90 does not interfere withfrequencies employed by computer monitors in common use. Time base forboth carrier frequency and frequency modulation is coordinated by clock92 through a crystal to promote accuracy and stability of the datatransmission. ID EEPROM is programmed with the unique identificationnumber assigned to each identification device 60 and carried in the datatransmitted by transmitter 90.

[0071] Microcontroller 91 of transmitter 90 emits a first data packetthrough a transmitting antenna 95 utilizing a Trinity (Base 3) protocolto make maximum use of available bandwidth while keeping receivercomplexity to a manageable level. An AM modulation technique is used,where 0 is defined as no carrier, 1 is 70% (−3 dB from MAX) of maximumcarrier and 2 is defined as maximum carrier level. A single transmissionis comprised of 20 TRITS (TRinary bITS) which include: one TRITidentifying the START of the data packet, two TRITS corresponding to thegroup identification number for the item, two TRITS of corresponding tothe status of the item, twelve TRITS corresponding to the uniqueidentification number of the item, and three TRITS relating to errordetection data. The first data packet may be organized in any othermanner or interpreted through other protocols commonly known in the art.Antenna 95 is a circuit loop antenna with a loop dimension ofapproximately 2 inches by 4 inches with an open-air coil of 20 mh.Antenna 95 may also encompass other designs and configuration eithercommercially available or known in the art.

[0072] Receivers 48 receive the first data packet from identificationdevice 60 through the use of first antenna 61 and second antenna 62.Both first antenna 61 and second antenna 62 generate two separatereceiving regions. The dual receiving regions of first antenna 61 andsecond antenna 62 work in tandem to determine the direction-of-travel,if any, of identification device 60 as it passes through a portalbetween zones 25 or domains 23. As shown in FIG. 4, the first antenna 61defines a receiving region A and the second antenna 62 defines areceiving region B. Receiving regions A and B are oriented about theportal between a first zone and second zone in a manner in which anyitem passing through the portal must pass through receiving regions Aand B.

[0073] As an item with an identification device 60 passes from a firstzone into a second zone through the portal connecting the zones,identification device 60 enters receiving region A provided by the firstantenna 61 of receiver 48. As identification device 60 enters the fieldA, its transmission field enters receiving field A causing antenna 61 toreceive the first data packet of identification device 60. Receiver 48converts the first data packet to a second data packet and appends adirection-of-travel code corresponding to receiving region B. Nodecomputer 28 receives the second data packet and determines a location ofthe item from the direction-of-travel code and the location of thereceiver. Once a new location of the item is determined, node computer28 transfers the identification number and location of the item tocontroller computer 26 to update the record associated with the uniqueidentification number.

[0074] If the item continues to move into the second zone,identification device 60 passes into receiving region B. Asidentification device 60 enters receiving region B, its transmission ofthe first data packet is received by antenna 62.

[0075] In contrast, if the item never enters receiving region B andleaves receiving region A, this movement would result in a loss oftransmission from identification device 60 in receiving region A andindicate to node computer 28 that the item never completed its movementbetween zones and instead returned to the first zone from which itoriginated. Accordingly, the dual antennae of each receiver 48positioned in each portal in environment 22 permits the tracking fromzone to zone and provides information in which to anticipate a projectedcourse of travel of an item without having to provide a vast array orgrid of receivers throughout environment 22 to calculate the location ofthe item at any point in time.

[0076]FIG. 5 illustrates a first domain 100 and a second domain 101 ofenvironment 122. First zone 102 and second zone 103 comprise domain 100,and third zone 104 and fourth zone 105 comprise domain 101. A firstportal 106 is a doorway from outside environment 122 and provides apoint of ingress and egress into and from first zone 102, domain 100,and environment 122. A second portal 107 is a doorway separating firstzone 102 from second zone 103 in domain 100. A third portal 108 is alower entrance to a stairwell connecting first and second domains 100and 101. A fourth portal 109 is the upper entrance to a stairwellconnecting the same domains. Likewise, a fifth portal 110 is a doorwayseparating third zone 104 from fourth zone 105 in domain 101.

[0077] A controller computer 126 monitors the movements of all items indomain 100 and a second controller computer 127 monitors the movementsof all items in domain 101. Both controller computers 126 and 127connect through an Ethernet network 112 with central server 124 thatcoordinates the activities of controller computers 126 and 127. Centralserver 124 connects through a programmatic link 114 with interface 135,a workstation running software permitting specialized managementinteraction of system 120. Interface 135 connects to workstation 137that maintains a backup of all records of items, as well as tracks thehistory of items' movements in environment 122 for security, assetaccounting, and human resource purposes.

[0078] A first node computer 128 tracks movement of items entering andexiting environment 122. Node computer 129 tracks movement of itemsbetween first zone 102 and second zone 103. A third node computer 130monitors items entering and exiting second domain 101, and a fourth nodecomputer 131 monitors items entering and exiting first domain 100. Afifth node computer 132 tracks the movement of items between third zone104 and fourth zone 105 in second domain 101. Node computers 128-130connect to a controller computer 126 via a multi-drop network 140 thatprovides for the exchange of data and power to operate each nodecomputer 128-130. Similarly, node computers 131 and 132 connect tosecond controller computer 127 through multi-drop network 140′.

[0079] First node computer 128 supports a first receiver 142 thatresides about first portal 106 and provides a first receiving region Aprovided by one antenna and a second receiving region B provided by asecond antenna. Controller computer 126 connects to a peripheral device,video camera 180 mounted to the wall near portal 106 that recordsdigital pictures of each item as it enters and leaves environment 122.The camera 180 connects directly to a video cord plugged into a portalbus of controller computer 126. Controller computer 126 operatescommercially available software to manipulate camera 180.

[0080] Second node computer 129 supports a second receiver 143 thatresides about second portal 107 and provides a first receiving region Cprovided by one antenna and a second receiving region D provided by asecond antenna. Node computer 129 also connects to a peripheral device,a digital voice synthesizer 192 with speaker system mounted on a wall inzone 102. In zone 103, node computer 130 connects to receiver 146 thatprovides dual low frequency, directional fields E and F at portal 108.

[0081] In domain 104, node computer 131 supports a receiver 144 and anilluminated, digital scrolling sign 150 mounted to wall and viewable totraffic between points-of-way 109, 110. Receiver 144 equipped with twoantennas that provide receiving regions G and H at portal 109. Likewise,node computer 132 provides a receiver 145 that provides receivingregions J and K in portal 110.

[0082] Arrow 180 shows the movement of an item II, in this case anemployee into environment 122. As item II enters portal 106, theidentification device which item I1 wears transmits a near frequencytransmission of a first data packet which includes a uniqueidentification number that corresponds to the identification device andthe item. An antenna that provides receiving region A receives thetransmission of the first data packet. First receiver 142 receives thefirst data packet, converts it into a second data packet appended with adirection-of-travel corresponding to receiving region A and sends thesecond data packet to first node computer 128. First node computerevaluates the second data packet and determines the location of item I1from the direction-of-travel code and the location of receiving region Ain environment 122. Once evaluated, the location of Item I1 is passed tocontroller computer 126 for recordation.

[0083] Controller 126 scans its database for a record identified by theunique identification number. In this case, controller computer 126 willfind no record for item I1 because the record for item I1 would bestored in central server 124 while item I1 is not present in any domain.For example, when an employee leaves environment 122 in the evening atthe end of the workday, the record for that item would be stored incentral server 124 until the item reenters environment 122. Here,controller computer 128 contacts central server 124 via network 112sending it the location information associated with item I1. Centralserver 124 responds by scanning its database for a record associatedwith unique identification number of item I1. Central server 124 findinga record indicating that item I1 had exited domain 100 and environment122 the previous evening, updates the record with the new locationinformation and sends the entire record to first controller computer 126to be stored in its database as long as item I1 remains in domain 100.Central server 124 may also send the record for item I1 to controllercomputer 126 to update the record with the new location information. Therecord for each item also contains information describing each item, itshome location, video and audio images of the items, constraints tomovements of the item, and alarm actions to be taken if the itemviolates the constraints.

[0084] As the item passes through low frequency field B, the uniqueidentification number transmitted by the identification device worn byitem I1 is received by first receiver 142 through the antenna thatprojects low frequency field B. First node computer 128 receives thedata from first receiver 142 and sends the location information for theitem to first controller computer 126. Simultaneously, controllercomputer 126 activates video camera 180 to capture a few seconds ofdigital video image of item I1 as it passes through portal 106. Thevideo image is stored as part of the record of item I1. First controllercomputer 126 evaluates the record and the new location information anddetermines item I1 passed through both fields A and B without enteringany other low frequency field. From this information, first controllercomputer 126 determines that item I1 moved in direction 180 and now islocated in zone 102. Central server 126 stores this information in therecord along with the time that item I1 entered the zone and its videoimage. Controller computer 126 then evaluates the current location ofitem I1 against the constraints to movement authorized in the record. Inthis case, the presence of item I1 in zone 102 is authorized requiringno further action.

[0085] In a similar fashion, if item I1 continues to move through zone102 and passes through portal 107, second receiver 143 picks uptransmissions as the identification device worn by item I1 passesthrough the low frequency fields C and D. As item I passes throughfields C and D, second node computer 129 receives the transmission fromreceiver 149 and communicates the unique identification number detectedand the location information to first controller computer 126.Controller computer 126 locates the record for item I1, evaluates themovement of item I1 through low frequency fields C and D and determinesfrom this information that item I1 has exited zone 102, entered zone 103and currently resides in zone 103. Once again, controller computer 126evaluates the current location of item I1 against the constraints tomovement listed in its records. Finding that item I1 is authorized tomove into zone 103, no further action is taken.

[0086]FIG. 5 illustrates another example of the present invention. Inthis example item I2 is a notebook computer assigned exclusively to zone105. Any movement out of zone 105 constitutes an unauthorized movement.Item I3 is a worker present in zone 105 who takes item I2 and transportsit elsewhere in environment 122. Item I3 takes item I2 and moves itthrough a portal 110 as illustrated by arrow 184. This movement causesthe identification devices assigned to both items I2 and I3 to passthrough low frequency fields K and J generated by the dual antennasconnected to receiver 145. The unique identification numbers emitted byidentification devices of items I2 and I3 are detected first in field Kand then field J. Node computer 132 receives these transmissions fromits antennas and transmits the location information for both items tosecond controller computer 127. Controller computer 127 scans itsdatabase for records associated with the unique identification numbersassociated with items I2 and I3. Finding records for each item,controller computer 127 evaluates the location information anddetermines that both items have moved from zone 105 to zone 104 andupdates the record. Next, the controller computer checks the record todetermine if the new location for each item constitutes an unauthorizedmovement designated by the constraints to movement associated with therecords at both items I2 and I3. According to the constraints ofmovement, item I3 is authorized to move throughout environment 122,however, the location of item I2 is restricted to zone 105. Finding anunauthorized movement, controller computer 127 reviews the record foritem I2 to finds two courses of action to be taken in response to theunauthorized movement: (1) if item I2 is in zone 104, flash anelectronic message on sign 150 located in zone 104 with a predefinedmessage such as “STOP! RETURN LAPTOP COMPUTER”; and (2) print apredefined alert message such as “WARNING LAPTOP COMPUTER OF ZONE 105HAS BEEN REMOVED AND IS PRESENTLY IN ZONE 104 WITHOUT AUTHORIZATION” onthe screen of user terminal 152, a security computer located in zone 104and connected to node computer 131 through one of its serial ports. Toperform these actions, controller computer 127 communicates with nodecomputer 131 through network 140′ informing it to activate electronicsign 150 to print the text string warning message sent to it bycontroller computer 127 and accesses security terminal 152 and print thedesired warning message in a window dedicated to system 120 open on thescreen of terminal 152. The warning message enables security personnelstationed at terminal 152 to learn of and take appropriate action tostop the unauthorized movement.

[0087] Alternatively, system 120 can be programmed to limit the movementof the laptop computer item I2 by selective individuals (items). Underthis scenario, the movement of item I2 is not bound by its physicallocation but rather by the personnel authorized to move item I2throughout the facility. The record of item I2 would provide constraintsto movements that personnel from a particular class, category, oridentification number may only move item I2 from zone 105. In this case,item I3 does not possess the requisite authorization to permit movementof item I2 from zone 105. As items I2 and I3 simultaneously pass throughfrequency fields K and J, receiver 145 receives the uniqueidentification signal from both items and transfers the signals receivedto node computer 132, which in turn transfers the location informationfor the items to node computer 127. Node computer 127 updates therecords for each item and determines that item I3, a worker, is movingitem I2 a laptop computer. The record for item I3 indicates that item I3does not belong to the class of workers authorized to move item I2.

[0088] Finding a violation to constraints to movement of item I2,controller computer 127 reviews the record for item I2 to find twocourses of action to be taken in response to the unauthorized movement:(1) if item I2 is in zone 104 and item I2 is moved by personnel not ofclass X, flash an electronic message on sign 150 located in zone 104with a predefined message such as “STOP! {name of personnel} RETURNLAPTOP COMPUTER”; and (2) print a predefined alert message such as“WARNING LAPTOP COMPUTER OF ZONE 105 HAS BEEN REMOVED BY {name ofpersonnel} AND IS PRESENTLY IN ZONE 104 WITHOUT AUTHORIZATION” onsecurity computer screen located in zone 104. Controller computer 127obtains the {name of personnel} from the record for item I3 to insertthe information into the text string. Controller computer 127communicates with node computer 131 through network 140 informing it toactivate electronic sign 150 and print a text string warning messagesent to it by controller computer 127. If item I3 sees the signdisplaying his name he will realize his unauthorized movement of item I2and return it to zone 105. Further, controller computer 127 communicatesto node computer 131 to access user terminal 152 and print the desiredwarning message in a window dedicated to system 120 open on the screenof terminal 152. The warning message enables security personnelstationed at terminal 152 to identify the individual responsible for theunauthorized movement and take appropriate action to stop theunauthorized movement.

[0089]FIG. 6 also illustrates an application of system 120 used tolocate and contact a person in environment 122. Item I4 is a doctor whoworks in domain 101. During his workday his record is maintained bycontroller computer 127 because item I4 performs his daily functionsentirely in domain 122. At the end of the day, item I4 departs domain101 through portal 109 leading downstairs to domain 100 as shown byarrow 188. As item I4 passes through frequency fields G and H, receiver144 receives the unique identification number transmitted from theidentification device worn by item I4. Receiver 144 passes the uniqueidentification number and the direction-of-travel signals correspondingto fields G and H, in that order, to node computer 131 that compiles thelocation information for item I4 and passes the location information tocontroller computer 127 to update the record for item I4. Controllercomputer 127 updates the record, evaluates the movement against theconstraints of movement for item I4 in its record, and identifies fromthe location that item I4 has passed from domain 101 and out of themonitoring control of controller computer 127. In this event, controllercomputer 127 passes the record of Item I4 through network 112 to centralserver 124, which stores the record in its database until item I4 entersa new domain.

[0090] Item I4 exits the stairwell and enters domain 100 passing throughfrequency fields F and E found in portal 108 as shown by arrow 190.Receiver 146 receives the unique identification number emitted from theidentification device worn by item I4 as item I4 passes throughfrequency fields F and E. Receiver 146 communication the uniqueidentification number to node computer 130 that determines the locationinformation for item I4. Node computer 130 transmits the locationinformation to controller computer 126. Controller computer 126 scansits database for the record corresponding to the unique identificationnumber assigned to item I4. Finding no record, controller computer 126queries central server 124 through network 112 for the record. Centralserver 124 locates the record in its database and passes the record foritem I4 to controller computer 126, which stores the record in itsdatabase updating the record with the location information of item I4.

[0091] At the same time, an emergency occurs in domain 101 and thepresence of item I4 is immediately required. A nurse working at terminal152, accesses a locate command from a window running system software forsystem 120. From this window, the nurse types in the name of item I4.Node computer 131 receives this input and immediately relays it tocontroller computer 127 attempts to locate a record associated with thename. Unable to locate a record associated with the name, controllercomputer 127 passes the information to central server 124. Centralserver 124 sends the name to all controller computers in environment 122requesting the location of item I4. Controller computer 126 receives theinformation and finds that it corresponds to the record assigned to itemI4 in its database. Controller computer 126 passes location informationon item I4 to central server 124, which in turn generates a message fordisplay in the window operating on terminal 152 and passes the messagethrough controller computer 127 and node computer 131 to terminal 152.

[0092] The nurse at terminal 152 seeing that item I4 is in domain 100and likely going to depart from environment 122 shortly, selects acommand from the window on terminal 152 to alert item I4 that hisassistance is needed immediately in domain 101. In this window, thenurse elects to both page the doctor and alert the doctor to theemergency through a peripheral warning device prior to leavingenvironment 122. In the window operating on terminal 152, the nursetypes a paging number with an emergency code to be sent to the pagerworn by item I4. Terminal 152 transmits the paging message through nodecomputer 131, relayed to controller computer 127, which passes it ontocentral server 124. Central server 124 connects with an in-house thirdparty communication system that incorporates paging system 195 andactivates the paging system 195 ordering a page to pager worn by itemI4.

[0093] Simultaneously, item I4 continues to move through domain 100.Item I4 enters point-of way 107 and passes through frequency fields Dand C, in that order, as shown by arrow 191. This movement is identifiedby receiver 143, which picks-up the unique identification transmissionfrom the identification device associated with item I4. Receiver 143passes the information to node computer 129, which in turn, passes thenew location information to controller computer 126. Controller computer126 updates the record associated with item I4 and passes new locationinformation to central server 124 to update the location of item I4 inthe window for user terminal 152.

[0094] Meanwhile, the nurse at terminal 152 elects to alert item I4 ofthe emergency directly through a voice synthesizer known to be installedin zone 102 for this purpose. In the window on terminal 152, the nursetypes a text message to be communicated. This text message is sentthrough node computer 131 to controller computer 127 to central server124, which routes the message to controller computer 126. Controllercomputer 126 maintains software to convert the text-based message to asignal interpretable by voice synthesizer 192. Controller computer 127sends the signal to node computer 129 that interfaces with voicesynthesizer 192. Voice synthesizer 192 projects an audio message intozone 102 directed to item I4. At about the same time, item I4 alsoreceived the page sent by third party pager system 190. Hearing theaudio message from synthesizer 192 and receiving the page, item I4responds by returning to domain 101 with system 120 continuouslytracking his movements and locations in the same manner as previouslydiscussed.

[0095] With reference to FIGS. 7-9, another exemplary embodiment of thepresent invention is illustrated. In the present embodiment, a system220 monitors and tracks a container 202 in an environment 222. In oneembodiment, the environment 222 is a transportation or shippingenvironment, such as an airport, truckyard, or railyard. In thefollowing discussion, the environment 222 will be described as anairport. However, the present invention is not limited to a specifictype of environment.

[0096] With specific reference to FIG. 7, the container 202 may be usedto deliver, ship, or move any number of types of cargo or equipmentwithin or into or out of an airport. A vehicle 204 and a trailer 206 maybe used to move the container 202. Other types of vehicles, for example,a forklift truck or other material handling machines or transportvehicle may also be used. One or more transmitters 290 may be used totrack the container 202, the vehicle 204, or the trailer 206 within,into or out of an airport. As shown in FIG. 7, in the exemplaryembodiment shown, a first transmitter 290A is coupled to the container202 and a second transmitter 290B is coupled to the vehicle 204.

[0097] With specific reference to FIG. 8, the system 220 includes anenterprise system 208 which is used to track the container 202throughout the airport environment 222. The airport environment 222 maybe divided into domains and zones (see above). For example, the airportenvironment 222 may include more than one airport. In the illustratedembodiment, the airport environment 222 includes first and secondairports 222A, 222B. The system 220 tracks the container 202 throughoutthe airport environment 222, including into and out of each airport222A, 222B. Information regarding the movement of the container 202 issent to and stored within the enterprise system 208. Information may beshared with external systems, such as a SABRE system 210 and/or an AIDAsystem 212. Access to the enterprise system 208 may also be providedexternally, such as through the internet 214.

[0098] Each transmitter 209A is assigned a unique identification numberand is adapted to transmit the unique identification number (see above).The system 220 includes at least one receiver 248 which is adapted toreceive the unique identification number from the transmitters 290, toresponsively determine a direction of travel of the transmitter 290, andto responsively generate a direction of travel code (see above). Asshown in the embodiment of FIG. 7, the transmitter 209A coupled to thecontainer 202 is assigned a first unique identification number and thetransmitter 209B coupled to the vehicle is assigned a second uniqueidentification number.

[0099] The system 220 also includes at least one node computer 228coupled to the receiver 248 and being adapted to control the receiver248, to receive the unique identification number and the direction oftravel code from the receiver, and to responsively determine a locationof the container 202 or the vehicle 204 as a function of the directionof travel code.

[0100] In one embodiment, the system 220 also includes a controllercomputer or node server 226 coupled to the node computer 228 and beingadapted to receive the first and second unique identification numbers,the location of the container 202, and the location of the vehicle 204from the node computer 228 and to compare the locations of the container202 and the vehicle 204 to at least one predefined constraint ofmovement of the container 202 and activating at least one warning deviceif the at least one predefined constraint of movement is violated. Forexample, the vehicle 204 may not have permission or authority to movethe container from one location to another location.

[0101] With reference to FIG. 9, a more detailed view of an exemplaryairport environment 222 is shown. As discussed above, the airportenvironment 222 may include a plurality of airports. For simplicity,only a single airport 222A is shown in FIG. 9, however, the airportenvironment 222 may include additional airports.

[0102] The airport 224 may include a loading zone 280 for at least oneaircraft 282. In the illustrated embodiment, first and second loadingzones 280A, 280B are shown for first and second aircraft 282A, 282B,respectively. Each loading zone 282A, 282B includes a portal and areceiver 248A, 248B located at the respective portal. In the illustratedembodiment, the receivers 248A, 248B are coupled to first and secondnode computers 228A, 228B. The first and second node computer 228A, 228Bare coupled to a first controlling computer 226A.

[0103] The airport 222 may also include at least one container area 284.In the illustrated embodiment, the airport 222 includes a pit area 284A,a cargo area 284B, a domestic mail area 284C, a maintenance area 284D,and an international mail area 284E. The container areas 284 are usedfor storage, loading/unloading, and maintenance, as needed. It should benoted that this arrangement of container areas is for illustrativepurposes only and the present invention is not limited to any sucharrangement.

[0104] Each container area 284 includes a portal and third, fourth,fifth, sixth and seventh receivers 248C, 248D, 248E, 248F, 248G locatedat the respective portal. Each receiver 248C, 248D, 248E, 248F, 248F iscoupled to third, fourth, fifth, sixth and seventh node computers 228C,228D, 228E, 228F, 228F, respectively. In the illustrated embodiment, thethird, fourth, and fifth node computers are coupled to a secondcontrolling computer 226B and the sixth and seventh node computers arecoupled to a third controlling computer 226C.

[0105] In the illustrated embodiment, the airport environment 222includes at least one ingress/egress area 286, such as a road orhighway. The ingress/egress area 286 including a portal and an eighthreceiver 248G located at the portal. The eighth receiver 248G is coupledto an eighth node computer 228G. The eighth node computer 228G iscoupled to the first controlling computer 226A.

[0106] As shown, the controlling computers 226A, 226B, 226C are coupledto the central server 124 (see above).

[0107] As stated above, the system 220 is programmed with a set ofpredefined rules or constraints against the movement of the containersand/or vehicles within the airport environment 222 and the real-time ornear real-time reporting of movement of the containers from specificarea to specific area or from specific area to unknown areas, from areasinside the airport to areas outside the airport, from the terminal tospecific flights or any other tracking requirements, as needed. Asdescribed above, the system 220 may also include one or more cameras forrecording events related to the movement of containers and/or vehicles.The system 220 may also include one or more signs or other signalingdevices for relaying messages related to the containers and/or vehiclesthroughout the airport environment.

[0108] Examples of logged or reported events may include:

[0109] When a container enters or departs from the terminal (cargo)property. The system 220 may also record which airline vehicle was beingutilized to facilitate the movement of the container.

[0110] When a container was placed onto or taken off of an aircraft.After the container was loaded into the cargo hold of an aircraft, thetransmitting device may shut down and cease transmitting until thecontainer is off loaded.

[0111] When the container passes through specified entrance/exit orcontrol points. Such points might include areas like the “pit” where aspecific egress road would be covered, the access point to a domesticmail facility and the access point to the staging area near aninternational terminal.

[0112] The current location of any or all vehicles and a historical logof their movement.

[0113] Other advantages and features of the present invention may beunderstood from a study of the drawings and appended claims.

1. A system for monitoring and tracking a container in an environment,comprising: a transmitter assigned a unique identification number andbeing coupled to the container, the transmitter being adapted totransmit the unique identification number; at least one receiver adaptedto receive the unique identification number from the transmitter, toresponsively determine a direction of travel of the transmitter, and toresponsively generate a direction of travel code; and, at least one nodecomputer coupled to the at least one receiver and being adapted tocontrol the receiver, to receive the unique identification number andthe direction of travel code from the at least one receiver, and toresponsively determine a location of the container as a function of thedirection of travel code.
 2. A system, as set forth in claim 1, furthercomprising: a vehicle, wherein the container is adapted to be moved bythe vehicle.
 3. A system, as set forth in claim 2, further comprising: atrailer adapted to be coupled to the vehicle and to receive thecontainer.
 4. A system, as set forth in claim 2, further comprising asecond transmitter assigned a second unique identification number andbeing coupled to the vehicle, the second transmitter being adapted totransmit the second unique identification number.
 5. A system, as setforth in claim 4, wherein the receiver is adapted to receive the secondunique identification number from the second transmitter, toresponsively determine a direction of travel of the second transmitterand to responsively generate a second direction of travel code.
 6. Asystem, as set forth in claim 5, wherein the at least one node computeris adapted to receive the second unique identification code and thesecond direction of travel code from the at least one receiver and toresponsively determine a location of the vehicle as a function of thesecond direction of travel code.
 7. A system, as set forth in claim 6,further comprising a controller computer coupled to the node computerand being adapted to receive the first and second unique identificationnumbers, the location of the container, and the location of the vehicleand to compare the locations of the container and the vehicle to atleast one predefined constraint of movement of the container andactivating at least one warning device if the at least one predefinedconstraint of movement is violated.
 8. A system, as set forth in claim1, wherein the environment includes at least two airports, each airportbeing divided into a plurality of zones.
 9. A system, as set forth inclaim 8, further including at least one portal located between eachairport and at least one receiver being located at each portal.
 10. Asystem, as set forth in claim 8, including at least one portal locatedbetween first and second zones and at least one receiver being locatedat each portal.
 11. A system, as set forth in claim 1, wherein theenvironment includes a loading zone for at least one aircraft, theloading zone including a portal, the receiver being located at theportal.
 12. A system, as set forth in claim 1, wherein the environmentincludes at least one container area, the container area including aportal, the receiver being located at the portal.
 13. A system, as setforth in claim 12, wherein the at least one container area is one of apit area, a cargo area, a domestic mail area, a maintenance area, and aninternational mail area.
 14. A system, as set forth in claim 1, whereinthe environment includes at least one ingress/egress area, theingress/egress area including a portal, the receiver being located atthe portal.
 15. A system, as set forth in claim 1, further comprising: acontroller computer coupled to the node computer and being adapted toreceive the unique identification number and the location of thecontainer from the node computer and to store the unique identificationnumber and the location of the container; and a central computerfacility coupled to the controller computer and being adapted to collectand store the unique identification number and the location of thecontainer for exportation from the system.
 16. A system, as set forth inclaim 1, wherein the transmitter generates at least one low frequencyelectromagnetic field.
 17. A system, as set forth in claim 16, whereinthe low frequency electromagnetic field operates at 125 kHz or less. 18.A system, as set forth in claim 15, wherein the receiver includes afirst antenna and second antenna, wherein the first antenna and thesecond antenna are placed at a portal in the environment and correspondto the direction of travel.
 19. A system, as set forth in claim 18,wherein the controller computer compares the location of the containerto at least one predefined constraint to movement of the containerstored in the controller computer to determine at least one violation inmovement of the container and activating at least one warning deviceconnected to the node computer, controller computer or central computerfacility if the at least one predefined constraint of movement isviolated.
 20. A system, as set forth in claim 19, wherein the warningdevice is selected from the group consisting of the following: (a) auser terminal or work station; (b) an electronic sign; (c) a voicesynthesizer; (d) a speaker; (e) a monitor; (f) a video or digitalcamera; or (g) a pager system.
 21. A system, as set forth in claim 19,wherein the central computer facility links with at least one thirdparty communication system to respond to the violation of movement ofthe container.
 22. A system, as set forth in claim 21, wherein the thirdparty communication system is selected from the group consisting of thefollowing: (a) a computer network; (b) a telecommunication network; or(c) a pager network.
 23. A system, as set forth in claim 15, wherein arecord maintained by the controller computer stores the uniqueidentification number and location of the container and the record beingtransferable to the central computer facility.
 24. A system, as setforth in claim 1, wherein the environment is a transportationenvironment.
 25. A system, as set forth in claim 1, wherein theenvironment is an airport environment.
 26. A system, as set forth inclaim 1, wherein the environment is a truckyard.
 27. A system, as setforth in claim 1, wherein the environment is a railyard.
 28. A system,as set forth in claim 1, wherein the receiver uses ultra wide bandtechnology and is further adapted to determine a distance between thereceiver and the transmitter.
 29. A system, as set forth in claim 28,wherein the node computer is adapted to track and store locationinformation based on signals received from the receivers.
 30. A methodfor monitoring and tracking at least one container in an environment,comprising: dividing the environment into a plurality of domains with atleast one portal separating the domains; providing the container with aunique identification number; developing an electronic record for theidentification number and recording a first location for the containerin a first computer; attaching a transmitter emitting the uniqueidentification number to the container; providing a receiver at theportal; moving the container through the portal; and, receiving theunique identification number by the receiver when the transmitter passesthrough the portal and responsively determining a direction of travel ofthe container and generating a direction of travel code.
 31. A method,as set forth in claim 30, including the steps of: sending theidentification number and the direction of travel code from the receiverto a second computer to verify the identification number and thedirection of travel code; determining a second location of the containerfrom the direction of travel code by the first computer; and sending theunique identification number and the location of the container from thesecond computer to the first computer to store the second location ofthe container in the electronic record of the container.
 32. A method,as set forth in claim 30, including the steps of dividing the domainsinto a plurality of zones with at least one portal separating the zones.33. A method, as set forth in claim 31, further comprising: defining atleast one constraint to movement of the container in the record of thecontainer; comparing the second location of the container to theconstraint to movement of the container by the first computer todetermine at least one violation in movement of the container; andactivating a warning device connected to the first computer or thesecond computer to respond to the violation in movement of thecontainer.
 34. A method, as set forth in claim 30, wherein thetransmitter generates at least one low frequency electromagnetic field.35. A method, as set forth in claim 34, wherein the low frequencyelectromagnetic field operates at 125 kHz or less.
 36. A method, as setforth in claim 30, wherein the receiver provides a first antenna andsecond antenna placed about the portal to receive the uniqueidentification number, wherein the first antenna and the second antennacorrespond to a separate direction of travel code.
 37. A method, as setforth in claim 33, wherein the warning device is selected from the groupconsisting of the following: (h) a user terminal or work station; (a) anelectronic sign; (b) a voice synthesizer; (c) a speaker; (d) a monitor;(e) a video or digital camera; or (f) a pager system.
 38. A method, asset forth in claim 31, further comprising: transferring the record withthe unique identification number and the second location to a thirdcomputer; and exporting the record with the unique identification numberand the second location to an independent third party system.
 39. Amethod, as set forth in claim 31, further comprising: transferring therecord with the unique identification number and the second location toa third computer; and communicating with at least one third partycommunication system to respond to the violation in movement of thecontainer.
 40. A method, as set forth in claim 39, wherein the thirdparty communication system is selected from the group consisting of thefollowing: (d) a computer network; (e) a telecommunication network; or(f) a pager network.
 41. A method, as set forth in claim 30, wherein theenvironment is a transportation environment.
 42. A method, as set forthin claim 30, wherein the environment is an airport environment.
 43. Amethod, as set forth in claim 30, wherein the environment is atruckyard.
 44. A method, as set forth in claim 30, wherein theenvironment is a railyard.
 45. A method, as set forth in claim 30,wherein the receiver uses ultra wide band technology the method includesthe step of determining a distance between the receiver and thetransmitter.
 46. A method, as set forth in claim 45, further includingthe step of tracking and storing location information based on signalsreceived from the receivers.
 47. A system for monitoring and tracking acontainer in an environment, comprising: a transmitter attached to thecontainer and being assigned a unique identification number, thetransmitter being adapted to transmit the unique identification number;a receiver located within the environment, the receiver being adapted toreceive the unique identification number and responsively determine adirection of travel code; a node computer coupled to the receiver, thenode computer being adapted to receive the unique identification codeand direction of travel code from the receiver and responsivelydetermine a location of the container: a controller computer coupled tothe node computer, the controller computer being adapted to receive theunique identification number and the location of the container from thenode computer and to store the unique identification number and thelocation of the container; and a central computer facility coupled tothe controller computer, the central computer facility being adapted tocollect and store the unique identification number and the location ofthe container for exportation from the system.
 48. A system, as set inclaim 47, wherein the receiver includes first and second antennas, thereceiver being adapted to generate first and second receiving fieldsusing the first and second antennas, respectively.
 49. A system, as setforth in claim 48, wherein the receiver is adapted to detect thecontainer in the first and second receiving fields.
 50. A system, as setin claim 49, wherein the direction of travel code is a function of thecontainer being detected in the first and second receiving fields.
 51. Asystem, as set forth in claim 47, wherein the environment is atransportation environment.
 52. A system, as set forth in claim 47,wherein the environment is an airport environment.
 53. A system, as setforth in claim 47, wherein the environment is a truckyard.
 54. A system,as set forth in claim 47, wherein the environment is a railyard.
 55. Asystem, as set forth in claim 47, wherein the receiver uses ultra wideband technology and is further adapted to determine a distance betweenthe receiver and the transmitter.
 56. A system, as set forth in claim47, wherein the node computer is adapted to track and store locationinformation based on signals received from the receivers.